/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package eu.fastl.dragster.web.filter;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.servlet.ServletOutputStream;

/**
 * {@link ServletOutputStream} which also writes every output to a cache.
 *
 * @author Ernst Fastl
 */
public class CachingServletOutputStream extends ServletOutputStream {

    private final ServletOutputStream stream;
    private final ByteArrayOutputStream cache = new ByteArrayOutputStream(100);

    public CachingServletOutputStream(ServletOutputStream stream) {
        this.stream = stream;
    }

    @Override
    public void write(int b) throws IOException {
        this.stream.write(b);
        this.cache.write(b);
    }

    @Override
    public void write(byte[] b) throws IOException {
        this.stream.write(b);
        this.cache.write(b);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        this.stream.write(b, off, len);
        this.cache.write(b, off, len);
    }

    @Override
    public void flush() throws IOException {
        this.stream.flush();
        this.cache.flush();
    }

    @Override
    public void close() throws IOException {
        this.stream.close();
        this.cache.close();
    }

    public byte[] getCachedContent(){
        return this.cache.toByteArray();
    }

    public void reset() {
        this.cache.reset();
    }
}
